The present invention relates to an image signal processor for a television (TV) set or a video cassette recorder (VCR), for example. More particularly, the invention relates to an apparatus for improving the visibility of an image to be displayed on a screen by enlarging the difference in signal level between bright and dark image areas.
FIG. 1 shows a general VCR including a mechanism block 1, a servo block 5, a signal processing block 3 and a control block 6.
In FIG. 1, a main controller 6 controls the other blocks so that a corresponding mode operation is performed according to the recording or reproduction mode of a VCR. When the VCR is in a recording mode, a luminance/chrominance (Y/C) processor 3 receives an image signal via an input/output portion 4 and processes the image signal to a signal having a recordable form. A preamplifier 2 connected to the Y/C processor 3 amplifies the input image signal to a predetermined magnitude. A mechanism block 1 is driven by a servo block 5 and records the amplified image signal on a medium such as a magnetic recording tape. The servo block 5 drives the mechanism block 1 under control of the main controller 6. When the VCR is in a reproduction mode, the mechanism block 1 is driven by the servo block 5, reads the image signal recorded on the recording medium, and outputs the read signal to the preamplifier 2. The preamplifier 2 amplifies the image signal output from the mechanism block 1 to a predetermined magnitude. The Y/C processor 3 processes the amplified image signal into a form capable of being displayed, to output the processed signal via the input/output portion 4.
However, an image processed and displayed in the VCR as described above is not easily viewed and thus requires improved visibility.